US2557657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water base drilling fluid
Assignee: Shell Development Co
•
Filing: 1948-10-13
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Granted: 1951-06-19
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Expires: 1968-10-13
Abstract
No abstract record available.
Inventors
- 👤 Henkes Rudolf August
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:03
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/20; C09K8/206
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
A WATER-BASE DRILLING FLUID FOR WELLS COMPRISING AN AQUEOUS SOLUTION OF A WATER-SOLUBLE SALT OF A POLYVALENT METAL, HAVING ADDED THERETO FROM ABOUT 0.5-TO ABOUT 5.0 PER CENT BY WEIGHT OF AN ORGANIC HYDROPHILIC COLLOID WHICH IS NOT COAGULATED BY POLYVALENT METAL SALTS AND FROM ABOUT 0.5 TO ABOUT 1.0 PER CENT BY WEIGHT OF LAMPBACK.
Claim 2
Dependent Claim
56 words
A WATER-BASE DRILLING FLUID FOR WELLS COMPRISING AN AQUEOUS SOLUTION OF A WATER-SOLUBLE SALT OF A POLYVALENT METAL, HAVING ADDED THERETO FROM ABOUT 0.5-TO ABOUT 5.0 PER CENT BY WEIGHT OF AN ORGANIC HYDROPHILIC COLLOID WHICH IS NOT COAGULATED BY POLYVALENT METAL SALTS AND FROM ABOUT 0.5 TO ABOUT 1.0 PER CENT BY WEIGHT OF LAMPBACK.
References Cited (Backward Citations)
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Cited
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-06-18 | 1954-12-18 | 1955-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-18 | 1958-12-18 | 1959-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-18 | 1962-12-18 | 1963-06-19 | $7700.00 | Window Closed / Lapsed |